生物谷:来自McGill大学蒙特利尔神经学研究中心(MNI)的科学家发现一个人类大脑的未知区域主要负责感知和储存有序视觉信息。这是更高级计划能力的基础,并且只在人类和其它灵长类中存在。
MNI认知神经科学主任Michael Petrides表示:“我们计划和操作信息的能力依赖于确定事物精确顺序的能力。狗、猫和老鼠等有很大的记忆容量,但它们的大脑可能没有捕捉事物精确顺序的能力。”
这一研究结果发表在8月13日的 Proceedings of the National Academy of Sciences上,在实验中,17位志愿者观察一系列黑白的抽象图像,科学家通过功能核磁共振对他们的大脑进行扫描。
Petrides表示:“在显示完第一组图像之后,志愿者马上重复观察第一、第二或是第三个图像,他们必须确定哪一个图像出现得较早。”在这一过程中,科学家观察志愿者大脑的活动情况,以确定在中背外侧额叶皮层(DLPFC)中,哪个区域负责获取以及保存视觉刺激的精确顺序。
实验中使用的抽象图案是精心选择的,它们难以用语言描述,这可以排除文字记忆的影响。Petrides说:“我们希望研究大脑大脑保存那些非文字记忆的事情的容量。有趣的是这些容量并不大。如果用文字记忆,我们可以记住7或8个,而对于抽象视觉则只有4或5个。”这些发现和了解一些神经功能问题相关,此外研究中的方法还可以帮助外科医生在手术中确定和避免某些区域。 (援引教育部科技发展中心)
原文链接:http://www.physorg.com/news106330255.html
原始出处:
Published online before print August 15, 2007
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0706220104
Neuroscience
Selective involvement of the mid-dorsolateral prefrontal cortex in the coding of the serial order of visual stimuli in working memory
( functional magnetic resonance imaging | human | serial-order memory )
Céline Amiez and Michael Petrides
Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, QC, Canada H3A 2B4
Communicated by Brenda Milner, McGill University, Montreal, Canada, July 4, 2007 (received for review December 18, 2006)
There is evidence that the primate prefrontal cortex is involved in the monitoring of the order in which stimuli occur. The prefrontal cortical areas, however, involved in the capacity of the human brain to encode and hold "in mind" the precise order of occurrence of a limited number of visual stimuli after a single exposure are not known. Changes in regional cerebral activity were measured with functional magnetic resonance imaging while subjects were coding the precise order of a short sequence of abstract visual stimuli. The results demonstrate the involvement of areas 46 and 9/46, within the mid-dorsolateral subdivision of the prefrontal cortex, in the coding of the precise order of a short sequence of visual stimuli in working memory, consistent with earlier results from monkey lesion studies. The availability of such detailed serial-order information in working memory allows high-level cognitive planning and mental manipulation, functions that depend on prefrontal cortex.